FEMA rates relative earthquake risk for Orange County as very high and reports modeled annual probability of 0.90% per year for the area.
FEMA summary
FEMA's profile for Orange County reports modeled annual probability of 0.90% per year for earthquake. FEMA's relative risk rating for the area is very high; the annualized frequency is a separate measure.
Hazard metrics cover FEMA county-equivalent geographies rather than individual addresses or parcels. Use local or state hazard maps before making a property, insurance, retrofit, or evacuation decision.
Select a hazard to inspect FEMA's figures for Orange County.
Earthquake
FEMA combines its area-wide loss estimate and community data in this relative rating. Event frequency appears separately below.
Relative FEMA score
99.9/100
FEMA models earthquake annualized frequency as the probability of a qualifying occurrence in a given year across the FEMA geography shown.
The area loss estimate combines FEMA's modeled losses to buildings, population, and agriculture across Orange County. It is not an estimate for a home or address.
City risk summary
For Costa Mesa, FEMA rates earthquake risk for Orange County as very high, with a relative score of 99.9/100. The next highest relative scores are wildfire at 99.8/100 and riverine flooding at 96.0/100.
Using FEMA data for Orange County, Costa Mesa is tied #42 among 111 covered California entries for earthquake risk; 13 entries share that score. Newport Beach is about 4.5 straight-line miles from the Costa Mesa map point and uses the same FEMA geography.
For homeowners and movers
Preparedness actions
Living in Costa Mesa? Learn how to handle water storage, sanitation, and security in a small space.
The map shows Costa Mesa. All FEMA figures on this page cover Orange County.
The FEMA figures cover Orange County. Address-level conditions require local maps, building records, and property details.
FEMA rates relative earthquake risk for Orange County as very high. Its modeled annual probability is 0.90% per year. Damage at a specific address also depends on the building, soil, elevation, and exact hazard zone.
Among 111 California cities covered by this directory, Costa Mesa is Tied #42 for relative earthquake risk based on FEMA's score for Orange County. 13 covered cities share this rank because they use the same FEMA geography. Homes within Costa Mesa can have different soil, elevation, construction, and hazard-zone conditions.
In FEMA's data for Orange County, the highest relative ratings are Earthquake (Very High), Wildfire (Relatively High), and Riverine Flooding (Relatively High). FEMA uses estimated losses and community data along with event frequency when assigning these ratings.
The hazard numbers cover Orange County. For an individual home, check local fault, flood, fire, evacuation, and building records for the exact address.
FEMA gives Orange County an overall relative risk rating of very high. Conditions at a specific home depend on its hazard zones, building type, maintenance, insurance, and access to evacuation routes and emergency services.
Start with this step: Check whether your home has an unbraced cripple wall, an unbolted foundation, or an unsecured water heater; use a qualified local professional for retrofit decisions. Secure tall furniture and heavy objects that could fall where people sleep or sit. Use Ready.gov Earthquakes and local emergency guidance for a complete plan.
Distances are measured between city coordinates.
| City | Distance | Earthquake rating | Relative score |
|---|---|---|---|
| Newport Beach, CA | 4 mi | Very High | 99.9 |
| Santa Ana, CA | 5 mi | Very High | 99.9 |
| Huntington Beach, CA | 5 mi | Very High | 99.9 |
| Westminster, CA | 8 mi | Very High | 99.9 |
| Irvine, CA | 8 mi | Very High | 99.9 |
Limited to products tagged for earthquake or general preparedness.
Disclosure: As an Amazon Associate, this site may earn from qualifying purchases.
Water
Filters up to 100,000 gallons. Essential when tap water is compromised.
View product
Water
Bombproof water storage. 5 gallons is the minimum for one person for 5 days.
View product
Power
600 lumens and rechargeable. Hands-free lighting is critical during power outages.
View productHazard metrics come from FEMA National Risk Index v1.19.0 (March 2023). City population and coordinates come from SimpleMaps US Cities Database. For current conditions, use official local maps, warnings, inspections, and professional advice.